Melatonin Secretion In Patients Research Articles

Variability in melatonin concentration in blood serum of patients with episodic migraine: a pilot study.

This study was aimed at assessing the possible effect of melatonin concentration on migraine. The serum concentration profile of melatonin in patients with diagnosed episodic migraine in the interictal period was compared to the profile in patients without migraine. Then, a correlation between the frequency and duration of migraine attacks, and the possible relationship between these parameters and melatonin levels in individual patients, was established. Melatonin secretion is related to migraine pathophysiology in many different ways. The study was conducted in a group of 58 subjects (48 women and 10 men). The study group comprised 29 patients (24 women and five men) diagnosed with migraine according to the International Classification of Headache Disorders (ICHD-3 beta), within the framework of the Outpatient Clinic at Bielanski Hospital in Warsaw and the Clinical Department of Neurology of the 2nd Faculty of Medicine (now known as the Faculty of Medical Sciences) at the Medical University of Warsaw, Poland. The control group consisted of 29 subjects (24 women and five men) with no headache. Blood samples for the determination of melatonin were collected at midnight, 2am, 3am, 4am and 6am. Melatonin level in a frozen serum of venous blood was determined by a radio-immuno-enzymatic method at the Department of Histology and Embryology of the Faculty of Veterinary Medicine at the University of Warmia and Mazury in Olsztyn, Poland. No statistically significant differences between the levels of melatonin and the averaged advances of melatonin profiles were observed in the examined and the control group. There were demonstrated medium negative correlations between the maximum value of melatonin and the duration of migraine (R = -0.4, p = 0.03). There were also observed statistically significant differences (p = 0.01) between the averaged advances of melatonin profiles, depending on the duration of migraine. Our study showed no abnormalities of melatonin secretion in patients with migraine during the interictal period. The results of studies available in the literature depend on the nature of the headache (episodic or chronic) and the time of measuring the concentration of melatonin (during a headache attack or in an interictal period).

Melatonin secretion in patients with Parkinson's disease receiving different-dose levodopa therapy

ObjectiveMelatonin is involved in the regulation of sleep and circadian biological rhythmicity; decreased melatonin secretion has been associated with circadian disruptions. Previous studies evaluating melatonin levels between patients with Parkinson's disease (PD) and controls without PD have found conflicting results; however, large-scale studies have not been performed. Our aim is to compare endogenous melatonin levels between patients with Parkinson's disease (PD) and non-PD older adults. MethodsIn this cross-sectional study on 201 outpatients with PD and 380 community-dwelling older Japanese adults (controls), urinary 6-sulfatoxymelatonin excretion was measured to estimate endogenous melatonin levels. ResultsUrinary 6-sulfatoxymelatonin excretion (UME) did not significantly differ overall between PD patients and non-PD controls, even after adjusting for age, gender, medications, sleep habits, and seasons. Among PD patients, a clear and robust dose–response association was found between levodopa equivalent dose and UME, independent of potential confounding factors, including Parkinson's disease severity. Compared with the lowest levodopa equivalent dose quartile group (mean levodopa equivalent dose, 132 mg/day), the highest group (mean levodopa equivalent dose, 973 mg/day) exhibited a 68% increase in UME (17.8 vs. 30.0 ng/mg cre, respectively). In addition, compared with the non-PD controls, PD patients receiving a lower levodopa equivalent dose displayed decreased UME and those receiving higher levodopa equivalent dose displayed increased UME. ConclusionOur study suggests that melatonin levels in PD patients receiving average levodopa doses are comparable with those in older adults, even after considering confounding factors. This association was modulated by daily levodopa dose in PD patients.

Melatonin secretion in patients with spinal cord injury

We evaluated the secretion of melatonin and the sleep quality in spinal cord injury patients versus healthy volunteers. This observational non-randomised study was conducted from June 2016 to January 2018 includes tetraplegics, paraplegics and healthy volunteers. Urinary 6-sulfatoxy-melatonin (U6SM) was measured during 5 period per day (8h–12h; 12h–16h; 16h–20h; 20h–00h; 00h–8h). Sleep quality was evaluated on Pittsburgh Sleep Quality Index and sleepiness on Epworth Sleepiness Scale. Correlation between U6SM dosage and sleep quality and sleepiness was analysed. Preliminary results 12 tetraplegic patients AIS A and B (10 men and 2 women) and 7 paraplegics AIS A and B were included in the study. No patient took neuroleptics or beta-blockers. No patient had a brain trauma associated. Eight tetraplegic patients (66.6%) had an absence of melatonin secretion, 4 (33.3%) had a decreased secretion with a shift of melatonin secretion. Unlike data of the literature, secretion of melatonin was not strictly normal in paraplegic patients: 4 (57.1%) had an absence of melatonin secretion, one T10 AIS A patient had a shift of melatonin secretion, 2 (28.5%) T9 and T10 AIS A patients had a normal melatonin secretion. The Pittsburgh Sleep Quality Index showed a poor sleep quality in tetraplegics (10.18 ± 4.62) versus (7.57 ± 3.64) in paraplegics and Epworth Sleepiness Scale showed a moderate sleepiness in tetraplegics (11.18 ± 4.30) versus (4.57 ± 2.50) in paraplegics. Secretion of melatonin is abnormal in patients with tetraplegia. It may partly explain sleep impairment of patients with tetraplegia. Further studies are needed to better understand the impact of this absence of melatonin secretion and to assess the effect of melatonin treatment in this population of patients.

Diurnal and nocturnal serum melatonin concentrations after treatment with continuous positive airway pressure in patients with obstructive sleep apnea.

INTRODUCTION Melatonin secretion, one of the main factors controlling the sleep-wake rhythm, may be disrupted in patients with sleep disorders. OBJECTIVES The aim of the study was to evaluate the profile of circadian melatonin secretion in patients with obstructive sleep apnea (OSA) and to assess the impact of 2-day and 3-month treatment with continuous airway pressure (CPAP) on diurnal and nocturnal serum melatonin levels. PATIENTS AND METHODS Serum melatonin levels were evaluated in 71 untreated patients with OSA and 18 healthy controls at 6 time points: 10 AM, 2 PM, 6 PM, 10 PM, 2 AM, and 6 AM. The measurements were repeated after 2 days and 3 months of CPAP treatment. RESULTS Melatonin secretion rhythm was altered in 25.4% of the patients with OSA. In patients with preserved secretion rhythm, the serum melatonin level was significantly lower at 2 AM and 6 AM, compared with healthy controls: 68.2 pg/ml (interquartile range [IQR], 30.1-109.8 pg/ml) vs 109.1 pg/ml (IQR, 63-167.9 pg/ml), P = 0.02 and 40.8 pg/ml (IQR, 20.8-73.2 pg/ml) vs 67.7 pg/ml (IQR, 32.7-131.7 pg/ml), P = 0.04, respectively. Melatonin levels did not change significantly after the 2-day and 3-month CPAP treatment. However, at 3 months, a shift of the peak melatonin concentration to 2 AM was observed in patients with an altered secretion rhythm. CONCLUSIONS OSA has a significant effect on serum melatonin levels. Neither short-term nor long-term CPAP treatment significantly changes melatonin concentrations; however, our results seem to indicate that a 3-month CPAP treatment may be helpful in restoring the physiological rhythm of melatonin secretion in patients with OSA.

Melatonin and cortisol secretion profile in patients with pineal cyst before and after pineal cyst resection

A pineal cyst is a benign affection of the human pineal gland on the borderline between pathology and normality. Only a small percentage of patients present with symptoms and a surgical treatment is indicated in highly selected cases. A melatonin secretion in patients with a pineal cyst before and after a pineal cyst resection has not been studied yet and the effect of surgery on human metabolism is unknown. The present study examined melatonin, cortisol and blood glucose secretion profiles perioperatively in a surgical group of 4 patients. The control group was represented by 3 asymptomatic patients with a pineal cyst. For each patient, 24-h circadian secretion curves of melatonin, cortisol and glycemia were acquired. An analysis of melatonin profiles showed an expected diurnal pattern with the night peak in patients before the surgery and in the control group. In contrast, melatonin levels in patients after the surgery were at their minimum throughout the whole 24-h period. The cortisol secretion was substantially increased in patients after the surgery. Blood glucose sampling showed no statistically significant differences. Clinical results demonstrated statistically significant headache relief measured by Visual Analogue Scale in patients after the surgery. Despite the small number of examined patients, we can conclude that patients with a pineal cyst preserved the physiological secretion of the hormone melatonin while patients who underwent the pineal cyst resection experienced a loss of endogenous pineal melatonin production, which equated with pinealectomy. Surprisingly, cortisol secretion substantially increased in patients after the surgery.

Circadian phase typing in idiopathic generalized epilepsy: Dim light melatonin onset and patterns of melatonin secretion-Semicurve findings in adult patients.

It has been debated in the literature whether patients with idiopathic generalized epilepsy (IGE) have a distinctive, evening-oriented chronotype. The few questionnaire-based studies that are available in the literature have conflicting results. The aim of our study was to define chronotype in patients with IGE by determining dim light melatonin onset (DLMO). Twenty adults diagnosed with IGE (grand mal on awakening [GM] in 7 cases and juvenile myoclonic epilepsy in 13 cases) were investigated by means of a face-to-face semistructured sleep interview, Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI) questionnaire, and a melatonin salivary test with DLMO determination. Eighteen healthy subjects (HC) and 28 patients affected with cryptogenic focal epilepsy (FE) served as controls. The mean MEQ score was significantly lower in patients with IGE than that in patients with FE (49.1±5.9 versus 56.1±8.7 P<0.01) but not significantly lower than that in HC (49.1±5.9 versus 49.3±8.6). Midsleep on free days corrected for sleep duration did not differ significantly between the three subject groups (04:59±01:21h, 04:37±01:17h, 04:29±00:52h). The mean DLMO time in patients with IGE (22:13±01:34h) occurred 49min later than that in HC (21.24±1h), and the melatonin surge within the 30-minute time interval after DLMO in patients with IGE was significantly lower than that in HC (1.51±2.7 versus 3.8±3.6pg/mL P=0.045). Subjective measures of chronotype do not indicate a definite evening-oriented chronotype in patients with IGE. However, the data concerning endogenous melatonin secretion indicate that patients with IGE tend to have a late circadian phase. Further studies are warranted in order to better define the late pattern of endogenous melatonin secretion in patients with IGE and to ascertain the role of this pattern in influencing behavioral chronotype in these subjects.

P2-25-4 - Melatonin Secretion in Patients with Breast Cancer Associated with Primary Hypertension

Objective: A number of experimental studies showed that melatonin, the main hormone of the pineal gland, exhibits chronobiological, anticancer and antihypertensive effects. It has been also known that endogenous lithium has similar chronobiological effect. The study was aimed to estimate melatonin secretion and serum levels of endogenous lithium in patients with breast cancer and concomitant primary arterial hypertension.Design and Methods: A total of 18 patients (aged from 37 to 64 years) with breast cancer and concomitant primary arterial hypertension (stage I by Joint National Committee) were studied. Control group was represented by 16 patients (aged from 34 to 69 years) with the same stage of breast cancer. Plasma levels of melatonin were estimated by liquid chromatography, serum levels of endogenous lithium were determined by atomic absorption spectroscopy.Result: Our results showed that plasma melatonin levels in patients with concomitant hypertension was almost 20 times lower (0.11±0.06 pcg/ml) than in control group (2.3< 0,38 pcg/ml, p < 0,01). While serum level of endogenous lithium in patients from control group (0,8 ± 0,03 mmol/l) was within the normal range (0,5 - 1,2 mmol/l), its serum level in patients with both cancer and hypertension was about ten times lower (0,07 ± 0,03 mmol/l, p < 0,001).Conclusion: Melatonin plasma levels and serum concentration of endogenous lithium significantly decrease in patients with breast cancer and arterial hypertension. Taking into consideration that both melatonin and endogenous lithium are chronobiologically active substances, we suggest that disturbances in circadian rhythm might contribute to the pathogenesis of arterial hypertension in patients with breast cancer.

949: Melatonin secretion in patients with breast cancer associated with primary hypertension

949: Melatonin secretion in patients with breast cancer associated with primary hypertension

Comparative Study of Window Glazing Systems Influence on Melatonin Secretion in Patients in the Hospital Wards

The interest in the research of non-visual effects on human health has risen during last decade rapidly. Daylight that has humans during our evolution adapted to is considered as healthy in its natural form. In reality, the daylight inside the buildings can be different in many parameters from the exterior one. Not only intensities and spatial distribution is altered, but also spectral composition can differ significantly. Daylight transmitted through transparent elements in buildings envelope and its shading devices is filtered and therefore can have different photobiological quality compared to the daylight in exterior. Effects of the altered light conditions can have negative impact on health mostly by people that spend time continually or permanently in those internal spaces, such as long term hospitalized patients in medical facilities. The aim of the research was to find out, whether the dramatic change in the transmittance of daylights blue component will evoke the change in melatonins secretion in patients urine samples. Despite great level of circadian disruption of observed subjects a typical changes in melatonin secretion were observed as a result of altered spectral transmittances due to different glazing systems.

Preliminary study: Evaluation of melatonin secretion in children and adolescents with type 1 diabetes mellitus.

Objective:Melatonin is an indolamine hormone, synthesized from tryptophan in the pineal gland primarily. Melatonin exerts both antioxidative and immunoregulatory roles but little is known about melatonin secretion in patients with type 1 diabetes mellitus (T1DM). The aim of this study was to measure serum melatonin levels in patients with T1DM and investigates their relationship with type 1 diabetes mellitus.Materials and Methods:Forty children and adolescents with T1DM (18 boys and 22 girls) and 30 healthy control subjects (17 boys and 13 girls) participated in the study. All patients followed in Pediatric Endocrinology and Metabolism Unit of Gaziantep University Faculty of Medicine and also control subjects had no hypertension, obesity, hyperlipidemia, anemia, and infection. Blood samples were collected during routine analysis, after overnight fasting. Serum melatonin levels were analyzed with ELISA.Results:There were no statistically significant differences related with age, sex, BMI distribution between diabetic group and control group. Mean diabetic duration was 2.89 ± 2.69 years. The variables were in the equation. Mean melatonin level in diabetic group was 6.75 ± 3.52 pg/ml and mean melatonin level in control group was 11.51 ± 4.74 pg/ml. Melatonin levels were significantly lower in diabetic group compared to controls (P < 0.01).Conclusions:Melatonin was associated with type 1 diabetes mellitus significantly. Because of the varied roles of melatonin in human metabolic rhythms, these results suggest a role of melatonin in maintaining normal rhythmicity. Melatonin may play role in preventing process of inflammation and oxidative stress.

Decreased daily melatonin levels in women with systemic lupus erythematosus - a short report.

The neuroendocrine system is known to influence immunity, but the precise interactions between different hormones and autoimmune disorders remain obscure. The present study aimed to investigate the role of daily serum melatonin concentrations in the development of systemic lupus erythematosus (SLE) in women. Case-control study. One-hundred and eleven SLE female patients and 46 healthy women were included in the study. Daily serum melatonin levels were investigated in all participants. SLE patients showed significantly lower daily melatonin levels in comparison to healthy women during the short photoperiod (17.75±7.13 pg/mL [16.05] vs. 21.63±6.60 pg/mL [20.10], p=0.012). Hormone concentrations were inversely related to the SLE activity index (SLEDAI) (r= -0.268, p=0.004), but they did not correlate to any particular American College Rheumatology (ACR) criterion (p>0.05 for all). Daily melatonin levels were decreased in women with systemic lupus erythematosus and correlated inversely to the activity of the autoimmune disease. Further studies are needed to clarify the importance of the pineal and extrapineal melatonin secretion in patients with systemic lupus erythematosus as well as the interrelations between hormones and autoimmunity.

Use of Beta-Blockers and Risk of Dementia in Elderly Patients

Use of Beta-Blockers and Risk of Dementia in Elderly Patients

Alteration of melatonin secretion in patients with type 2 diabetes and proliferative diabetic retinopathy

Background:The purpose of this study was to evaluate the dynamics of plasma melatonin secretion in patients with type 2 diabetes mellitus and diabetic retinopathy.Methods:Plasma melatonin levels were measured by high-performance liquid chromatography in 56 patients. Patients were divided into a diabetic group (30 patients) and a nondiabetic group (26 patients). The diabetic group was divided further into a proliferative diabetic retinopathy (PDR) group (n = 14) and a nonproliferative diabetic retinopathy (NPDR) group (n = 16). Plasma melatonin levels obtained at midnight and 3 am were compared between the groups.Results:Nighttime melatonin levels were significantly lower in the diabetic group than in the nondiabetic group (P < 0.03) and lower in the PDR group than in the nondiabetic and NPDR groups (P < 0.01 and P < 0.03, respectively), but no significant difference was found between the nondiabetic and NPDR groups. The daytime melatonin level did not significantly differ between the nondiabetic and diabetic groups or between the nondiabetic, NPDR, and PDR groups.Conclusion:The nighttime melatonin level is altered in patients with diabetes and PDR but not in diabetic patients without PDR. Although patients with PDR may have various dysfunctions that affect melatonin secretion more severely, advanced dysfunction of retinal light perception may cause altered melatonin secretion. Alteration of melatonin secretion may accelerate further occurrence of complications in diabetic patients.

Postoperative neuropsychological change and its underlying mechanism in patients undergoing coronary artery bypass grafting

The high incidence of neuropsychologic deficits after cardiac surgery, including cognitive dysfunction and mood status, has significantly influenced the prognosis, outcome of treatment and long-term quality of life of patients. With a circadian secretion pattern, melatonin and cortisol are capable of modulating the human physiological processes and neuropsychological status, whereas disorder of their secretion pattern may lead to many diseases. However, it is unclear whether neuroendocrine variations are related to the neuropsychologic status in patients undergoing coronary artery bypass grafting (CABG). Forty male patients scheduled for CABG with hypothermic cardiopulmonary bypass (CPB) (n = 20) or off-pump coronary artery bypass (OPCAB) (n = 20) were studied. Blood samples were taken intraoperatively at specific time-points and every 3 hours within the first postoperative 24 hours to determine plasma concentrations of melatonin and cortisol. A neuropsychologic test battery including depression and anxiety was administered preoperatively and 7 to 10 days postoperatively. Statistical methods included the nonparametric analysis, multiple linear regression and cosinor analysis. The patients in the CPB group exhibited more severe neuropsychologic deficits and more anxious than those in the OPCAB group after surgery. In both groups, patients were more depressed postoperatively than preoperatively and recovered 3 months after surgery. Depression and anxiety were correlated with some factors of cognitive dysfunctions. In the postoperative 24 hours, 2 patients in the CPB group, and 6 patients in the OPCAB group showed a circadian rhythm of melatonin secretion. As for cortisol secretion, there were 3 patients in the CPB group and 7 in the OPCAB group respectively. Parameters of circadian rhythm of melatonin in the CPB group and those of secretion rhythm of cortisol in both groups were correlated with depression and some neuropsychologic tests. The incidence of neuropsychological deficits was higher in patients receiving CABG with CPB than in those without CPB. The status of mood may contribute to the perioperative cognitive dysfunctions. The disordered circadian rhythm of melatonin secretion in patients undergoing CABG with CPB and the disordered cortisol secretion may correlate directly or indirectly through mood with neuropsychological deficits.

Role of Melatonin in the Pathophysiology of Migraine

The pineal gland and its secretory product, melatonin, have been implicated in the pathophysiology of migraine, as well as some of its comorbid disorders. Supporting this view, many migraineurs are susceptible to various environmental triggers that influence the secretion of melatonin from the pineal gland, and many prodromal symptoms are probably generated in the hypothalamus, a brain region that provides input into the pineal gland to modulate the secretion of melatonin. In addition, studies have shown abnormalities in melatonin secretion in patients who experience migraine and an improvement in migraine following administration of melatonin. However, the dysfunction in melatonin secretion in migraineurs may simply be a marker of hypothalamic dysfunction or neuronal hyperexcitability, leading to migraine susceptibility. It is also possible that abnormal melatonin secretion leads to decreased inhibitory neurotransmitter activity, decreased inhibition of the release of calcitonin gene-related peptide (CGRP) from activation of the trigeminal system, or less analgesia. Whatever its role in the pathogenesis of migraine, melatonin may prove to be a useful therapy. Future studies are necessary to further elucidate whether melatonin is a well tolerated, beneficial therapy, and to determine the optimal dose and formulation of melatonin for use in migraine therapy.

Bilateral Oculosympathetic Paresis Associated With Loss of Nocturnal Melatonin Secretion in Patients With Spinal Cord Injury

Background: Lesions along the sympathetic pathway to the eye produce oculosympathetic paresis (OSP, Horner’s syndrome). The oculosympathetic pathway descends from the hypothalamus through the cervical spinal cord and ascends to the superior cervical ganglion (SCG), which innervates sympathetic targets in the ipsilateral face and eye. This pathway appears to closely co-localize with a similar retino-pineal neural pathway from the hypothalamus through the cervical spinal cord and SCG to the pineal gland. As such, lesions along this shared pathway, such as occur in neurologically complete injury to the cervical spinal cord (tetraplegia), would be predicted to result in simultaneous OSP and loss of pineal melatonin production. Loss of melatonin production may contribute to the pervasive sleep disruption observed in patients with tetraplegia.Methods: We assessed the presence of OSP by photographic documentation of ptosis and pupillary dilation response to cocaine eye drops in 5 individuals with neurologically complete damage to their upper thoracic or lower cervical spinal cord. We correlated these results with an analysis of the pattern of melatonin production in these same individuals.Results: Bilateral OSP was present in individuals with cervical spinal cord injury; each also lacked significant production of melatonin. No evidence of OSP was observed in the 2 individuals with thoracic spinal cord injury below the level of the oculosympathetic pathway. Both had normal circadian rhythms of melatonin production, with timing and amplitude of the rhythm within normal parameters.Conclusion: The presence of bilateral oculosympathetic paresis can be predictive of the complete loss of the nocturnal production of melatonin.

Perioperative melatonin circadian secretion in patients undergoing coronary artery bypass grafting surgery

To investigate the circadian rhythm of perioperative melatonin secretion in patients undergoing coronary artery bypass grafting surgery. Forty male patients scheduled for elective coronary artery bypass grafting surgery (CABG) under hypothermic cardiopulmonary bypass (CPB) or off-pump were allocated into two groups of 20 patients: CPB group and off-pump group. Blood samples were withdrawn from all patients immediately before the induction of anesthesia (baseline), 10 min after the induction of anesthesia, 10 min after heparinization, 30 min after commencement of CPB (or 2h after skin incision), before reversal of heparin with protamine, at the end of surgery, and. every 3 hours after operation until the twenty-fourth hour. The plasma concentration of melatonin was measured by using enzyme-linked immunosorbent assay. The plasma melatonin concentrations during and after CPB were higher than the baseline value in the CPB group. There were no differences in the melatonin concentrations in the off-pump group. In the CPB group the melatonin concentrations after induction, during CPB, and after CPB were 7.2 +/- 3.4, 10.5 +/- 5.2, and 9.5 +/- 4.0 respectively, all significantly higher than those in the off-pump (5.5 +/- 2.5, 6.3 +/- 2.0, and 5.7 +/- 2.1 respectively, all P < 0.05). During the twenty-four hours after operation, two patients in the CPB group and six patients in the off-pump group showed circadian rhythm of melatonin secretion. The perioperative circadian rhythm of melatonin secretion in patients undergoing CABG surgery with CPB or off-pump is disturbed, however relatively more patients under off-pump group regain secretion rhythm of melatonin in the immediate postoperative period. CPB may be one of the reasons for perioperative melatonin circadian secretion disturbance.

Melatonin secretion and increased daytime sleepiness in childhood craniopharyngioma patients – First experiences in therapeutic melatonin substitution

Craniopharyngioma is a rare dysontogenetic benign tumor. Patients frequently suffer from endocrine deficiencies, sleep disturbances and obesity due to pituitary and hypothalamic lesions. A self-assessment daytime sleepiness questionnaire (German version of the Epworth Sleepiness Scale [ESS]) was used to evaluate 79 patients with childhood craniopharyngioma. Because hypothalamic lesions may explain daytime sleepiness in craniopharyngioma patients, salivary melatonin and cortisol concentrations were examined in obese and non-obese craniopharyngioma patients (n=79), patients with hypothalamic pilocytic astrocytoma (n=19), and control subjects (n=30). Using a linear prediction model analyzing the influence of BMI and tumor diagnosis on diurnal salivary melatonin and cortisol levels we found that morning salivary melatonin levels were significantly and independently related to BMI (p-value in F-test: 0.004) and tumor diagnosis (p-value in F-test: 0.032). Also for nighttime salivary melatonin levels significant relations with BMI (p-value in F-test: <0.001) and tumor diagnosis (p-value in F-test: 0.025) were detectable. Melatonin concentrations in saliva of craniopharyngioma patients collected at nighttime or in the morning showed a significant (p<0.01; p<0.05) inverse correlation (Spearman r: –0.42; –0.31) with the patient's ESS score. Severely obese craniopharyngioma patients and severely obese hypothalamic tumor patients had similar patterns of melatonin secretion. Differences in terms of morning and nighttime salivary melatonin concentrations were not detectable between normal weight controls and normal weight patients with craniopharyngioma or hypothalamic tumor. Differences in salivary cortisol concentrations were not related to impaired melatonin secretion in patients with childhood craniopharyngioma. A pilot study on efficacy of melatonin substitution (6mg/d) in childhood craniopharyngioma patients with severe daytime sleepiness (n=12) showed a significant improvement based on ESS and activity protocols. We speculate that hypothalamic lesions might be responsible for both obesity and daytime sleepiness. As decreased nocturnal melatonin levels were associated with increased daytime sleepiness, BMI and hypothalamic tumor diagnosis, further studies on the beneficial effects of melatonin substitution on daytime sleepiness and weight control in these patients are warranted. (www.kraniopharyngeom.com)

Perioperative melatonin secretion in patients undergoing coronary artery bypass grafting.

Melatonin, a neurohormone, plays an important role in adjusting the "biological clock" in humans. We sought to describe perioperative patterns of melatonin secretion in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass (CPB). After IRB approval and written informed consent, 12 male patients scheduled for elective coronary artery bypass grafting under hypothermic CPB were enrolled in the study. During anesthesia, patients' eyes were carefully covered to prevent light effects. Blood samples were taken at specific time points during surgery, every 3 h in the immediate postoperative period, and for 24 h from 6:00 PM of Postoperative Day 2 until 6:00 PM of Postoperative Day 3. Plasma melatonin and cortisol concentrations were measured by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. During surgery, plasma melatonin concentrations were below the minimum sensitivity concentration, yet small concentrations, without circadian variation, were detected during the immediate postoperative period. During Postoperative Days 2 and 3, circadian secretion patterns of melatonin were present in 10 patients and showed an inverse correlation with light intensity (r = 0.480; P < 0.01). Plasma cortisol concentrations in the immediate postoperative period were significantly larger than those before the induction of anesthesia (P < 0.01). Only three patients regained circadian secretion of cortisol. We concluded that melatonin and cortisol secretion was disrupted during cardiac surgery with CPB and in the immediate postoperative period. However, circadian rhythms of melatonin were present in most patients from Postoperative Day 2. Only 30% of the patients regained circadian rhythm of cortisol secretion. Melatonin is a hormone that plays an important role in adjusting the biological clock in humans and that regulates secretion of various other hormones. We studied melatonin secretion in patients undergoing cardiac surgery with cardiopulmonary bypass. Melatonin secretion was disturbed during and immediately after surgery but had recovered a circadian rhythm 24 h later, raising the question of whether melatonin should be supplemented before cardiac surgery.

Perioperative melatonin secretion in patients undergoing coronary artery bypass graft surgery: a pilot study

Melatonin, a neurohormone, plays important roles in adjusting the 'biological clock', and is an important mediator in many normal physiological functions [1]. Melatonin disturbances have been linked to neuropsychological dysfunction and postoperative delirium [2]. However, there have been no reports on postoperative melatonin levels to date. The aim of the present study was to observe perioperative melatonin secretion in patients undergoing coronary artery bypass graft surgery.